Postgres 14

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select version();

version

PostgreSQL 14.5 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-10), 64-bit

SELECT 1

create table limit_total_length( id         integer  generated always as identity
                               , text_array text[]
                                 check (length(replace(array_to_string( text_array ,','), ',','')) <= 25)
                               );

CREATE TABLE

 insert into limit_total_length(text_array)
      values ( array['0123456789','abcedeghij'])
           , ( array['0123456789','abcedeghij','uvwxy'])

INSERT 0 2

select * 
  from limit_total_length;

id
text_array

1
{0123456789,abcedeghij}

2
{0123456789,abcedeghij,uvwxy}

SELECT 2

-- total characters in array exceeds limit
insert into limit_total_length(text_array)
      values ( array['0123456789','abcedeghij','uvwxyz01']);

ERROR:  new row for relation "limit_total_length" violates check constraint "limit_total_length_text_array_check"
DETAIL:  Failing row contains (3, {0123456789,abcedeghij,uvwxyz01}).